This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Studies show that hypertension, also known as high blood pressure, occurs more commonly in African-Americans than in Caucasians. For this reason, this study will focus on hypertension in African-Americans and examine factors that may cause hypertension to be found more often in this population. The factor that will be examined in this study is a condition known as oxidative stress. Oxidative stress is a condition where too much oxygen is produced in the blood and the cells begin to decline in quality. Two chemicals, such as, reactive oxygen species (ROS) and F2-isoprostane, when found in high levels in the blood, can cause this condition. The purpose of this study is to measure these chemicals and determine if African-Americans with high blood pressure have higher levels of these chemicals than in subjects with normal blood pressure readings.